Pallet heat rib shield

ABSTRACT

The ribs of a pallet used in sintering machines and the like has loosely fitting heat shields arranged in spaced-apart relation over the upper surface of the ribs, and such heat shields contact the pallet ribs only at selected spaced-apart locations.

I United States Patent 1 51 3,638,928 Mitchell Feb. 1, 1972 [54] PALLET HEAT RIB SHIELD 2,322,873 6/1943 Moriarty ..263/28 I 3,063,696 11/1962 Culling ....266/2l I M h P [72] nventor Hartman ltc ell, lttsburgh, Pa 3,191,763 6/1965 Hagenbookm /5 X 1 Asslgnw pp p y, 3,384,355 5/1968 Ban ..263/28 [22] Filed: Aug 28 1969 3,420,5 l2 1/l969 Irvine, Jr. et al ..266/2l PP 853,652 Primary Examiner-John .I.Camby Attorney-Sherman H. Barber and Olin E. Williams [52] US. Cl ..263/28, 263/50, 266/21 [51 1 1m. Cl ....F27b 9/00, F27b 21/02 ABSTRACT [58] Field of Search ..263/28, 50; 266/21 The ribs ofa pallet used in simering machines and the like has loosely fitting heat shields arranged in spaced-apart relation [56] References Cited over the upper surface of the ribs, and such heat shields con- UNITED STATES PATENTS tact the pallet ribs only at selected spaced-apart locations. 3,559,967 2/1971 Werner ..263/28 4 Claims, 4 Drawing Figures 1 PAIENIEBFEa are mean 3.638.928

I NVEN TOR. HAPTMAA/ Al/TC/IEZL JZWMAAM BACKGROUND OF THE INVENTION The present invention relates to sintering and, more particu-- larly, to removable caps or heat shields over the top of the pallet ribs of sintering machine pellets.

Experience shows that, after a sintering machine has been in service for a period of time, theindividual pallets, on which the material to be indurated is supported, undergo progressive sagging crosswise of the machine. The sagging is caused by a combination of mechanical cycling and thermal loads. The mechanical cycling and the thermal loads produce compressive yielding in the uppermost fibers of the pallet cross-ribs, which effects a shortening of the top of the cross-rib, wherefore the cross-ribs sag downward.

The top surfaces of the cross-ribs, being closest to the heat of sintering or induration, become much hotter than the lower portion of the ribs. Wherefore, due to the restraining influence of the cooler bottom portion, the upsetting action occurs in the upper portion. Y

Eventually, the sagging progresses to the point where the machine can no longer be operated. At this time, it is necessary to either straighten the pallets or to replace them.

Heretofore, a number of suggestions have been made, which are known from the prior art, to shield the top portion of the pallet ribs from the heat of sintering or induration. Attempts have been made to produce removable upper portions of a pallet, but such efiorts have not proved to be entirely satisfactory, mainly because the pallet frame upper portion 7 still warped or sagged.

The present invention is directed to a novel heat shield for the ribs of a pallet and such heat shields significantly reduce the warping and sagging of sintering pallets.

SUMMARY OF THE INVENTION A sintering pallet having spaced-apart ribs is provided with a protective heat shield that surrounds the top portion of the rib and with pad means disposed between the heat shield and the rib to provide an air gap therebetween.

For a further understanding of the present invention and for advantages and features thereof, reference may be made to the following description taken in conjunction with accompanying drawings which show for the purpose of exemplification a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In theidrawing:

FIG. 1 is a plan view of a portion of a sintering pallet that incorporates the present invention;

FIG. 2 is an elevational view along line 11-]! of FIG. 1;

FIG. 3 is an end view along line III-III of FIG. 1 with a portion of the structure broken away for clarification purposes; and

FIG. 4 is a modification of an embodiment of the invention.

DETAILED DESCRIPTION the ribs being connected together at their extremities by "side members 17.

The ribs 13 support a plurality of grate bars 19 and are retained in position by outwardly extending lugs 21, 23 that cooperate with a shaped head portion 25 of each elongate rib 13. The head portion 25, as shown in FIG. 3, is rectangular in cross section, and the rib I3 main body portion is generally tra ezoidal in cross section.

IG. 4 illustrates a modified form of rib 27 having a. rounded head portion 29. Other shaped head portions may be used if they are preferred over the two forms shown.

The top surface of the head portions 25, 29 are provided with a plurality of spaced apart small circular pads 31 that may be integrally cast with the ribs or secured to the rib, in any suitable manner.

The head portions 25, 29 are covered by removable heat shields 33, 35 respectively. The heat shield 33 is adapted to the shape of the rectangular head portion 25, and the heat shield 35 is adapted to the shape of the rounded heat portion 29, as shown in FIGS. 3 and 4.

It will be apparent from FIGS. 3 and 4 that the small pads 31 prevent the heat shields 33, 35 from making contact with the respective head portions 25, 29 and airgaps 37, 39 are formed between the heat shields and the head portions.

Actually, the grate bars 19 rest on the heat shields 33, 35 and the grate bars are shaped, as shown in FIG. 4, to conform to the arcuate surface of the heat shield 35.

The heat shields are easily and quickly replaced by simply removing the side plate 41 of the pallet 11 and sliding the heat shield laterally after removing the grate bars 19. New heat shields may be installed, the grate bars replaced, and the side plate bolted into place.

Those skilled in the art will recognize in the present invention several significant features and advantages among which are:

That the heat shields, being spaced apart from the top portion of the pallet rib, protect the rib portion from radiated and conducted heat, whereby the rate at which sagging occurs in the pallet is reduced markedly; and

That the heat shields may be quickly and easily removed from the ribs, and that replacement heat shields may be readily and easily installed.

What is claimed is:

1. In a sintering machine having a plurality of interconnected pallets comprised of spaced-apart ribs adapted to support a plurality of grate bars, the combination with said spaced-apart ribs of:

a. protective means surrounding the top portion of said rib;

and

b. a plurality of pads disposed between said rib and said protective means for maintaining said protective means in spaced-apart relation from said rib.

2. The invention of claim 1 wherein:

a. the top portion of said rib has an angular cross section;

and

b. said protective means is angularly shaped to surround said top portion.

3. The invention of claim I wherein:

a. said top portion of said rib is round; and

b. said protective means is round to surround said top portion.

4. A pallet for a sintering machine comprising:

a. a frame that includes side members and a plurality of spaced-apart ribs connecting said side members;

b. protective means surrounding the top portion of each said rib;

c. a plurality of pads disposed between said rib and said protective means for maintaining said protective means in spaced-apart relation to said rib;

d. a plurality of grate bars disposed between said ribs and coactive with said protective means; and

e. side plates mounted to said side members. 

1. In a sintering machine having a plurality of interconnected pallets comprised of spaced-apart ribs adapted to support a plurality of grate bars, the combination with said spaced-apart ribs of: a. protective means surrounding the top portion of said rib; and b. a plurality of pads disposed between said rib and said protective means for maintaining said protective means in spaced-apart relation from said rib.
 2. The invention of claim 1 wherein: a. the top portion of said rib has an angular cross section; and b. said protective means is angularly shaped to surround said top portion.
 3. The invention of claim 1 wherein: a. said top portion of said rib is round; and b. said protective means is round to surround said top portion.
 4. A pallet for a sintering machine comprising: a. a frame that includes side members and a plurality of spaced-apart ribs connecting said side members; b. protective means surrounding the top portion of each said rib; c. a plurality of pads disposed between said rib and said protective means for maintaining said protective means in spaced-apart relation to said rib; d. a plurality of grate bars disposed between said ribs and coactive with said protective means; and e. side plates mounted to said side members. 